Extended hybrid bonding with a photonic interface

An apparatus, comprising

• a first substrate, comprising a first optical waveguide embedded in the first substrate;
• a second substrate, comprising a second optical waveguide embedded in the second substrate;
• and
• a third optical waveguide embedded in the first substrate and the second substrate, wherein the third optical waveguide overlaps a portion of the first optical waveguide and a portion of the second optical waveguide;
• and
• wherein the first substrate is bonded to the second substrate, and wherein an interface between the first substrate and the second substrate is between a top surface of the third optical waveguide and a bottom surface of the third optical waveguide.

An apparatus, comprising:

• a first substrate, comprising:
• a first optical input at a first surface of the first substrate;
• and
• a first optical waveguide coupled to the first optical input, wherein the first optical waveguide extends horizontally and vertically within the first substrate;
• and
• a second substrate that is bonded to the first substrate, wherein the second substrate comprises:
• a second optical input at a second surface of the second substrate, wherein the second optical input directly contacts the first optical input;
• and
• a second optical waveguide coupled to the second optical input, wherein the second optical waveguide extends horizontally and vertically within the second substrate.